Retrofitting non-digital billboards have proven to be expensive, time consuming and labor intensive. Moreover, simply removing an older non-digital billboard and replacing it with a new digital billboard has not proven entirely satisfactory since older installed, non-digital, billboard panels represent substantial capital outlays making it financially difficult, if not impossible, to discard such panels arbitrarily for replacement with digital panels. Therefore, it would be highly desirable to have a new and improved billboard retrofit kit that can be easily and quickly installed on an existing billboard, without the need to replace or discard existing non-digital panels. The new and improved billboard retrofit kit should greatly improve displayed information, displaying such advertising information, with improved resolution, contrast and brightness characteristics. Moreover, the retrofit kit should enable the displayed content to be easily and quickly changed or updated, either on-site or remotely, at a lesser cost than updating the content of an older non-digital billboard. Finally, installation of the kit in the field on an existing billboard structure should not require any special installation equipment and should be able to be accomplished by one or two individuals in a fast and convenient manner.